1. Field of the Invention
The present invention relates to a structure of an accommodation device (a refill unit) for an ink cartridge mounted on an ink-jet recording apparatus (an ink-jet printer).
2. Description of the Related Art
In general, an ink-jet recording apparatus, such as a printer, records an image on a recording medium with ink which is ejected from a recording head. The recording head is mounted on a carriage which reciprocates in a direction (in a main scanning direction) perpendicular to a direction in which the recording medium is fed. Ink which is stored in advance in a cartridge-type ink tank (an ink cartridge) is supplied to the recording head from the ink cartridge.
There are generally two types of ink cartridges broadly distinguished by their location in the ink-jet recording apparatus: what is called, an on-carriage type and an off-carriage type. In the on-carriage type ink cartridge, ink is supplied to a recording head from an ink cartridge which is removably accommodated in a required case mounted on a reciprocable carriage. On the other hand, in the off-carriage type ink cartridge, an ink cartridge is accommodated in a required case mounted somewhere in a housing of an ink-jet recording apparatus except on a carriage. Ink is supplied to the recording head through an ink supply tube or the like from the case in which the cartridge is accommodated.
Generally, in any types of the ink cartridges, replacement of the ink cartridge to new one is required when an amount of ink remaining in the ink cartridge becomes small.
JP-2002-79690A discloses an example of an ink cartridge wherein an ink supply needle for leading ink into the recording head is fitted on a plug element which is provided in an area of an ink supply opening in the cartridge. This prevents ink from leaking between the needle and the plug element. To this end, the plug element is made of an elastic member, such as a rubber material, and includes a guide tube and a plug portion. The guide tube is formed so as to fit to a recess portion defined by a tubular member which is projected from an outer peripheral portion of the ink supply needle in the recording head. The plug portion is formed radially inside the guide tube for closely contact with the ink supply needle. Between the guide tube and the plug portion, a space is provided. The plug portion has a tubular portion for guiding the ink supply needle and a tapered portion for sealing an ink inlet.
However, the structure of the ink cartridge disclosed in JP-2002-79690A suffers from the following problem. With each removal of the ink cartridge, ink adhering to a peripheral surface of the ink supply needle flows to a basal portion thereof and accumulates in the recess portion. When a new ink cartridge is inserted, the accumulated ink transfers to an end surface or a peripheral surface of the guide tube of the ink cartridge. This causes the ink to stain a body of the ink-jet recording apparatus, a desk, or a garment of a user when the cartridge is inserted or removed, or in a state in which the cartridge has been removed.